Murphy (Peter O'Toole) is a sailor working on a merchant vessel during the years of the Second World War. When his ship is fatally attacked by a U-Boat while travelling along the coast of Venezuela, Murphy manages to escape, and thanks to French engineer Brezan (Philippe Noiret), he is nursed back to health at a nearby Quaker mission. Murphy then determines to have his revenge on the U-Boat, and when he gets his hands on a plane, he realises that this is exactly what he needs to blow the enemy vessel out of the water.